when pushing the pin for the floorplate, you need to push the floorplate rearward simultaneously, and it should drop out. As far as loads, the 243 starts at pressures where the original loadings stop for those mausers, I have two of them 1893 long rifle & 1895 carbine and keep the pressures at 44,000 CUP (7x57) and below, they perform wonderfully and are pretty accurate for 80+ year old guns (mine were made in the 30's).